<template>
    <div class="list" ref="wrapper">
        <div>
            <div class="area">
                <div class="title border-topbottom">当前城市</div>
                <div class="button-list">
                    <div class="button-warpper">
                        <div class="button">{{this.currentCity}}</div>
                    </div>
                </div>
            </div>
            <div class="area">
                <div class="title border-topbottom">热门城市</div>
                <div class="button-list">
                    <div 
                        class="button-warpper"
                        v-for="item of hotCities"
                        :key="item.id"
                        @click="handelCityClick(item.name)"
                    >
                        <div class="button">{{item.name}}</div>
                    </div>
                </div>
            </div>
            <div 
                class="area"
                v-for="(item, key) of cities"
                :key="key"
                :ref="key"
            >
                <div class="title border-topbottom">{{key}}</div>
                <div class="item-list">
                    <div 
                        class="item border-bottom"
                        v-for="innerItem of item"
                        :key="innerItem.id"
                        @click="handelCityClick(innerItem.name)"
                    >
                    {{innerItem.name}}
                    </div>
                </div>
            </div>
        </div>
    </div>
</template>

<script>
//引入移动端滚动条插件betterscroll，文档：https://www.npmjs.com/package/better-scroll
import BScroll from 'better-scroll'
import { mapState, mapMutations } from 'vuex'
export default {
  name :'CityList',
  props: {
      hotCities : Array,
      cities : Object,
      letter : String
  }, 
  computed: {
    ...mapState({
        currentCity: 'city'
    })
  },
  methods: {
      handelCityClick (city) {
          //this.$store.commit('changeCity', city)
          this.changeCity(city)
          this.$router.push('/')
      },
      ...mapMutations(['changeCity'])
  }, 
  //监听器letter的变化
  watch: {
    letter () {
      if (this.letter) {
        const element = this.$refs[this.letter][0]
        //console.log(element)
        this.scroll.scrollToElement(element)
      }
    }
  },
  mounted () {
      //使用betterscroll
      this.scroll = new BScroll(this.$refs.wrapper)
  },
}
</script>

<style lang="stylus" scoped>
    .border-topbottom
        &:before
            border-color #ccc
         &:after
            border-color #ccc
    .border-bottom
        &:before
            border-color #ccc
    .list
        overflow hidden
        position absolute
        top 1.8rem
        left 0
        right 0
        bottom 0
        .title
            line-height .54rem
            background #eeeeee
            padding-left .2rem 
            color #666
            font-size .26rem
        .button-list
            overflow hidden
            padding .1rem
            padding .1rem .6rem .1rem .1rem
            .button-warpper
                float left
                width 33.33%
                .button
                    text-align center
                    margin .1rem
                    border solid .02rem #ccc
                    padding .1rem 0
                    border-radius .06rem
        .item-list
            .item
                line-height .76rem
                padding-left .3rem
</style>

